Compost & Organic “Waste”

Providence’s cafeteria, like most commercial kitchens, sends our discarded organics to the municipal landfill. Organics decomposing in landfills is one of the primary sources of methane gas emissions in Manitoba.

Finding realistic alternatives to our current practice was one of three projects being undertaken by the Business/Government Relations class in the Fall 2011 semester. (The other two were hosting an all-party debate on rural economic policy and working on establishing a rural transit system in our area.)

The questions addressed by this project were:

  • How can we efficiently collect the organics discarded during food preparation? (By “efficiently” we mean achieving our goals without adding significantly to staff worktime.)
  • Can those discards be used in the composting in our community garden?
  • How can we connect with other commercial kitchens in our area to deal with all of the organics those kitchens discard?
  • What other businesses in our area have significant amounts of organic discards, and can we work with them in mutually-beneficial ways?
  • How can we integrate what we are doing with ideas being developed by surrounding municipalities?
  • How can we ingegrate what we are doing with windrow composting happening on farms in our area?

Preliminary Results

Our cafeteria produces, on average, about 30kg of organic waste a day. This amount varies considerably based on what activities are happening on campus.

The calculation is also affected by what is included and excluded as organic waste. Some composting systems can only process pre-consumer waste (material left over from food preparation) while others can accept post-consumer waste (plate scrapings) as well.

Six main options were considered:

  1. Adding to the enclosed composters we have already in our community garden. 
    • Alternative considered under this option included adding more stationary units, or adding tumblers.
    • The most viable available unit under this option appears to be 12 cubic foot Sterling Rotocomposter. This has the largest capacity, would not be unsightly, and can be easily turned. However, these could not process post-consumer waste, and a considerable number would be required to process all (or even most) of our organic waste.
    • The biggest drawback with this alternative is that these systems are designed for household organic recycling and would not scale up easily to institutional size. This is particularly problematic in that our intention is to develop a system which could be duplicated at other institutions.
  2. Building our own larger-scale tumbler.
    • We also considered building our own tumbler system, rather than going with the pre-cast commerciapl plastic models reviewed in option 1. Options included adapting large drainage pipes, including ones made from recycled plastic.
    • This would be less expensive than buying commercial tumblers. After considerable discussion, this option was discarded primarily because we lack the expertise to do the research and development needed to turn this into a viable idea.
    • If we could find a suitable partner to help us with the research and development, this still remains as an interesting option.
  3. Creating an open-air composting system, similar to what is done at Red River College.
    • Red River was considered as a model because they have been doing organic waste composting for a decade, on a scale much larger than we would need.
    • We toured their facility as part of our research. Their system for collecting waste within their kitchen system could well serve as a model for us, but the processing of the compost could not. They use a “big pile” system—essentially two large piles of compost, turned by a front end loader. The piles are located outdoors in an unused area of their campus.
    • There are at least two reasons why this would not be suitable for us—we don’t have a location on our campus that would be similarly out of sight and, because our campus is on a river, this system would attract considerably more animals than it does at Red River.
  4. Adding a semi-enclosed box system
    • A potential compromise between the first two options, a semi-enclosed system, has the advantage of being scalable (unlike the first option), and does not allow compost to lie loose on the ground (unlike the second).
    • However, it still has a number of disadvantages, including attracting animals. This option appears to be more suitable for garden and leaf-based compost than for cateteria compost.
  5. Integrating with Compo-Stages Manitoba Services Co-op, a windrow composting cooperative developed for local farmers and municipalities.
    • This cooperative uses a Backhus windrow turner. It travels to farms and municipal landfill sites in southern Manitoba and is capable of handling a wide variety of compost materials, including post-consumer organics.
    • The Buller Centre hosted one of the early meetings of this cooperative and is interested in seeing it develop.
    • Unfortunately, this system is designed for operations that are considerably larger than ours. As well, it would require us to either establish a compost windrow on our campus, or transport our organics off-site.
  6. Nioex Systems’ BIOvator
    • A spin-off company from Puratone, a company in the hog industry, the BIOvator is a closed-vessel system capable of handling a wide variety of organic waste, including both pre- and post-consumer organics. It produces a high-quality end product that we could use in our community garden.
    • The BIOvator unit comes in a number of sizes. Most of them are larger than we would need, but the smallest appears to be viable for us.
    • The cost, however—approximately $20,000—is beyond what we can afford.
    • We have initiated discussions with a nearby greenhouse operation–Schreimers–about combining forces to install one at their greenhouse. This means that some off-campus transportation would be required, but the distance from our campus to the greenhouse would be signfiicantly less than transporting to a farm or municipal landfill using the windrow compositing system summarized in option 5.
    • All things considered, this seems to be the most viable alternative for us.

If you know of a composting or organic waste project elsewhere we should know about, please email us.


Compost & Organic “Waste” — 15 Comments

  1. Kevin Hildebrand
    I am in the recycling group, and I’m just in the process of gathering information.

    I was wondering if we are just focusing on local organic recycling, or are we also looking at it from a broader perspective as well? If someone could get back to me that would be good.

  2. Jan 2011 news release on a rural Manitoba initiative for composting for both farms and municipalities.